Engine Coolant Temperature Sensor Replacement
How are engine coolant temperature sensor issues diagnosed?
When diagnosing a check engine light related to the engine coolant temperature sensor, the servicing technician will connect a professional scan tool to the vehicle via the on-board diagnostics port under the dashboard. The technician will read the information stored in the vehicle's computer, and compare that data to actual conditions. If the temperature readings from the computer are incorrect, the technician will suspect the coolant temperature sensor. The sensor circuit and sensor will be tested to verify the diagnosis.
How is a engine coolant temperature sensor replaced?
After the diagnosis has been confirmed, the technician will unplug the electrical connector from the sensor prior to removal. The sensor may be bench tested for further confirmation. If required, sealant will be applied to the new sensors threads before being inserted into its place in the thermostat housing, engine block, or other. The cooling system will then be refilled, bled of any air, and the vehicle will be checked for normal operation. If there is significant corrosion noted in the cooling system, the technician may recommend a coolant flush.
RepairPal Recommendations for engine coolant temperature sensor issues
Engine coolant flushes are one of the most common services needlessly recommended, raising repair costs. However, there is a schedule for when these services should be performed. The factory scheduled maintenance section in the owner’s manual provides information for the customer concerning which maintenance items should be performed, and when they are needed. We always recommend following the factory scheduled maintenance intervals for preventive maintenance. If a leak is being repaired, and the coolant must be drained and replaced, flushing the coolant system should be performed if excessive corrosion is present, or if the factory scheduled service interval has been surpassed.
What to look out for when dealing with engine coolant temperature sensor issues
Without the appropriate scan tools or diagnostic experience, symptoms of a failed coolant temperature sensor may lead you in the wrong direction. Rough running, poor acceleration, decreased fuel economy, and even overheating can result from a faulty temperature sensor. It is important that the vehicle is properly diagnosed before replacing any parts.
Can I replace the engine coolant temperature sensor myself?
The average DIYer can maintain the engine cooling system without much trouble. However, diagnosing the system when problems arise can be a daunting task if the function of each individual component is not fully understood. If the temperature sensor is confirmed to be faulty, replacement of the sensor is typically easy for the moderately experienced DIYer. If knowledge of the engine cooling system and diagnosing cooling issues are lacking, this repair should be handed to a certified technician.
